The purpose of our proposed research is to exploit the uses of aziridinium salts in the synthesis of alkaloids which have important physiological activity. We have shown in preliminary studies that carbon nucleophiles will attack aziridinium salts to yield aminoethylated products. This reaction is similar in some respects to the well-known Mannich reaction, and we hope to explore its many potential uses. We will first explore the scope of the reaction to determine the limitations on the carbon nucleophiles. We next will utilize the aziridinium ring opening as the key step in a new and direct total synthesis of morphine. We have already carried out a substantial amount of preliminary work, and have obtained positive results. We also propose to examine the synthesis of 14-substituted morphine derivatives, as well as the synthesis of benzomorphans, homobenzomorphans, and benzazocines. These types of compounds are all known to have useful analgesic activity. We believe that aziridinium salts will be useful in the synthesis of a wide variety of alkaloid types, and we therefore intend to work on the synthesis of a typical benzylisoquinoline alkaloid such as laudanosine, as well as explore a new route to the synthesis of pyrrolizidine alkaloids. We are particularly intent on devision a synthesis of the anti-tumor agent, indicine N-oxide, based on aziridinium ion chemistry.